scholarly journals Sampling Methods for Adventive Trissolcus japonicus (Hymenoptera: Scelionidae) in a Wild Tree Host of Halyomorpha halys (Hemiptera: Pentatomidae)

2019 ◽  
Vol 112 (4) ◽  
pp. 1997-2000 ◽  
Author(s):  
N F Quinn ◽  
E J Talamas ◽  
T C Leskey ◽  
J C Bergh

Abstract Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) is an invasive pest that has established in much of the United States. Adventive populations of an effective Asian egg parasitoid of H. halys, Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae), have been detected in several states, including Virginia, and its geographic range is expanding. Documenting changes in its distribution and abundance have thus become key research priorities. For these specific purposes, surveillance of T. japonicus over large geographic areas using sentinel H. halys egg masses may not be optimally efficient, and examination of alternative sampling tactics is warranted. In 2016, sentinel H. halys egg masses were deployed as vertical transects in the canopy of female Ailanthus altissima (Mill.) Swingle (Sapindales: Simaroubaceae) in Virginia. A brief follow-up study in 2016 using yellow sticky traps deployed in the same trees yielded captures of T. japonicus, leading to a comparison of vertical transects of sentinel eggs and yellow sticky traps in 2017. Both methods yielded T. japonicus detections only in the middle and upper tree canopies, whereas other known H. halys parasitoids were detected in the lower, middle, or upper canopies. Based on this information, a method for deploying yellow sticky traps in the middle canopy of H. halys host trees was assessed in 2017, yielding T. japonicus captures. A comparison of estimated time inputs revealed that traps were more efficient than sentinel eggs in this regard. Results are discussed in relation to the utility of each sampling method to address specific questions about the range expansion and ecology of T. japonicus.

2021 ◽  
Author(s):  
Dalton C Ludwick ◽  
Layne B Leake ◽  
William R Morrison ◽  
Jesús R Lara ◽  
Mark S Hoddle ◽  
...  

Abstract Halyomorpha halys (Stål) is an invasive pest in the United States and other countries. In its native range, H. halys eggs are parasitized by a co-evolved parasitoid, Trissolcus japonicus (Ashmead). In the United States, T. japonicus, a classical biological control candidate, is being redistributed in many states where adventive populations exist. To establish if H. halys egg holding conditions affect T. japonicus foraging behavior or successful parasitism, naïve, female parasitoids from an adventive population were allowed to forage in laboratory bioassay arenas with either fresh or frozen (−20 or −80°C) egg masses, the latter held for five durations ranging from 1 h to 112 d. Parasitoid movements were recorded for 1 h. Thereafter, parasitoids were transferred with the same egg mass for 23 h. Additionally, female parasitoids from a quarantine colony were exposed to: 1) pairs of fresh egg masses and egg masses frozen at −40°C (>24 h) or 2) a single fresh egg mass or egg mass frozen at −40°C (<1 h). All exposed egg masses were held to assess progeny emergence. In the foraging bioassay, holding temperature and storage duration appeared to influence host-finding and host quality. Egg masses held at −80°C and fresh egg masses resulted in significantly greater levels of parasitism and progeny emergence compared with eggs held at −20°C. No differences were recorded between egg masses held at −40°C for ≤1 h and fresh egg masses. These results will help refine methods for preparation of egg masses for sentinel monitoring and parasitoid mass rearing protocols.


Author(s):  
Warren H. L. Wong ◽  
Matt A. Walz ◽  
Angela B. Oscienny ◽  
Jade L. Sherwood ◽  
Paul K. Abram

AbstractAn effective stockpiling method for egg masses of the invasive brown marmorated stink bug (Halyomorpha halys [Stål]; Hemiptera: Pentatomidae) would be useful for rearing and field studies of its egg parasitoid Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae). The current method of stockpiling H. halys egg masses at sub-zero temperatures has lethal and sublethal fitness consequences for T. japonicus. We show that parasitoid emergence from egg masses refrigerated at 8°C for up to two months before parasitism is higher than from frozen egg masses and usually has minimal or no sublethal fitness effects (sex ratio, development time, activity, fecundity, longevity, and weight) on emerging T. japonicus. Only after two months of host egg refrigeration did the emergence of T. japonicus begin to decrease significantly (by 9.6% relative to untreated viable egg masses), whereas egg masses previously frozen at -80°C had a 58.8% reduction in parasitoid emergence after 14 days of storage. Refrigerated egg masses that were subsequently exposed to average field temperatures (warm: 22.9°C; cool: 13.2°C) were still suitable for T. japonicus parasitism after 7 days, while viable egg masses exposed to warm temperatures for 7 days before parasitism had 24.1% lower parasitoid emergence. Our results demonstrate that refrigeration at 8°C, while resulting in complete mortality of H. halys embryos after 10 days, are more suitable for T. japonicus parasitism than those stored at sub-zero temperatures. The quantity and quality of H. halys eggs that can be stockpiled with this method could facilitate T. japonicus laboratory colony maintenance, field monitoring, and releases.


Insects ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 833
Author(s):  
Dalton C. Ludwick ◽  
Jessica Patterson ◽  
Layne B. Leake ◽  
Lee Carper ◽  
Tracy C. Leskey

Halyomorpha halys (Stål, 1855) (Hemiptera: Pentatomidae) is an invasive species in the United States, where it has caused significant damage to specialty crops, including apples. While integrated pest management techniques have been developed for H. halys in apple, including spray application techniques, it is unknown how these techniques affect foraging, adventive Trissolcus japonicus (Ashmead, 1904) (Hymenoptera: Scelionidae), and its offspring. In this study, egg masses (unparasitized and 2 and 7 day parasitized pre-treatment) were placed in apple orchards in treated and untreated locations that received full block insecticide applications or reduced application techniques, including border row or alternate row middle applications. Bifenthrin, thiamethoxam + λ-cyhalothrin, clothianidin, and methomyl were evaluated. Egg masses were retrieved 24 h after spray applications. For 2 and 7 day parasitized pre-treatment, adult T. japonicus emergence was recorded from each egg mass. For unparasitized egg masses, T. japonicus females were given 24 h to forage and oviposit on post-treatment egg masses with female survivorship, and adult emergence from egg masses was recorded. Female survivorship was significantly lower on post-treatment egg masses retrieved from areas receiving bifenthrin applications. Emergence from post-treatment egg masses was affected by thiamethoxam + λ-cyhalothrin, bifenthrin, and methomyl in some treated areas, whereas less impact was observed on 2 and 7 day pre-treatment parasitized egg masses in general. These data provide further insights into H. halys management and the potential impact of T. japonicus in sprayed orchard agroecosystems.


Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 118
Author(s):  
Nicole F. Quinn ◽  
Elijah J. Talamas ◽  
Tracy C. Leskey ◽  
J. Christopher Bergh

Trissolcus japonicus, an important egg parasitoid of Halyomorpha halys in Asia, was first detected in the USA in 2014. To evaluate the effect of habitat and the seasonality of T. japonicus detections in the USA, yellow sticky traps were placed in the canopy of Ailanthus altissima growing at the edge of isolated patches of trees, windbreaks, and woodlots in northern Virginia in 2018 and 2019. In both years, captures occurred from May to September, and peaked in July and August. While T. japonicus was detected in all habitats, there was not a consistent effect of habitat type on capture frequency. To evaluate tree species effects on T. japonicus captures, in 2017 and 2018, yellow sticky traps deployed in the canopy of A. altissima bordering apple orchards were paired with a nearby trap in one of several wild tree species along a common woods edge. In 2019, these traps were deployed in A. altissima, black walnut, and black locust growing in the same windbreaks. No consistent association between captures of T. japonicus or native parasitoids of H. halys and the tree species sampled was observed among years. Results are discussed in relation to the ecology and sampling optimization of T. japonicus.


2019 ◽  
Vol 19 (4) ◽  
Author(s):  
Joshua M Milnes ◽  
Elizabeth H Beers

Abstract Trissolcus japonicus (Ashmead), an Asian parasitoid of Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), was first detected in North America in 2014. Although testing in quarantine facilities as a candidate for classical biological control is ongoing, adventive populations have appeared in multiple sites in the United States, Canada, and Europe. Extensive laboratory testing of T. japonicus against other North American pentatomids and H. halys has revealed a higher rate of parasitism of H. halys, but not complete host specificity. However, laboratory tests are necessarily artificial, in which many host finding and acceptance cues may be circumvented. We offered sentinel egg masses of three native pentatomid (Hemiptera: Pentatomidae) pest species (Chinavia hilaris (Say), Euschistus conspersus Uhler, and Chlorochroa ligata (Say)) in a field paired-host assay in an area with a well-established adventive population of T. japonicus near Vancouver, WA. Overall, 67% of the H. halys egg masses were parasitized by T. japonicus during the 2-yr study. Despite the ‘worst case’ scenario for a field test (close proximity of the paired egg masses), the rate of parasitism (% eggs producing adult wasps) on all three native species was significantly less (0.4–8%) than that on H. halys eggs (77%). The levels of successful parasitism of T. japonicus of the three species are C. hilaris > E. conspersus > C. ligata. The potential impact of T. japonicus on these pentatomids is probably minimal.


Insects ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 840
Author(s):  
Barbara Bittau ◽  
Maria Luisa Dindo ◽  
Giovanni Burgio ◽  
Giuseppino Sabbatini-Peverieri ◽  
Kim Alan Hoelmer ◽  
...  

Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), a pest of Asian origin, has been causing severe damage to Italian agriculture. The application of classical biological control by the release of Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae), an exotic egg parasitoid, appears to be one promising solution. In Italy, releases of T. japonicus in the field were authorized in 2020. In this study, some parameters that could influence the rearing of T. japonicus in insectaries were investigated. A significantly higher production of progeny was observed on host eggs stored at 6 °C (86.5%) compared to −24 °C (48.8%) for up to two months prior to exposure to parasitism. There were no significant differences in progeny production from single females in a vial provided with only one egg mass (83.2%) or 10 females inside a cage with 6 egg masses (83.9%). The exposure of parasitoids to refrigerated (6 °C) egg masses of H. halys for 72 h led to a significantly higher production of progeny (62.1%) compared to shorter exposures for 48 (44.0%) or 24 h (37.1%). A decline in production of progeny by the same female was detected between the first (62.1%) and the second parasitization (41.3%). Adult parasitoids stored at 16 °C for up to 90 days had an 87.1% survival rate, but a significant decrease in progeny production was detected. These parameters could be adjusted when rearing T. japonicus for specific aims such as the production of individuals for field release or colony maintenance.


Insects ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 413
Author(s):  
Hanna R. McIntosh ◽  
Victoria P. Skillman ◽  
Gracie Galindo ◽  
Jana C. Lee

The egg parasitoid Trissolcus japonicus is the main candidate for classical biocontrol of the invasive agricultural pest Halyomorpha halys. The efficacy of classical biocontrol depends on the parasitoid’s survival and conservation in the agroecosystem. Most parasitoid species rely on floral nectar as a food source, thus identifying nectar sources for T. japonicus is critical. We evaluated the impact of eight flowering plant species on T. japonicus survival in the lab by exposing unfed wasps to flowers inside vials. We also measured the wasps’ nutrient levels to confirm feeding and energy storage using anthrone and vanillin assays adapted for T. japonicus. Buckwheat, cilantro, and dill provided the best nectar sources for T. japonicus by improving median survival by 15, 3.5, and 17.5 days compared to water. These three nectar sources increased wasps’ sugar levels, and cilantro and dill also increased glycogen levels. Sweet alyssum, marigold, crimson clover, yellow mustard, and phacelia did not improve wasp survival or nutrient reserves. Further research is needed to determine if these flowers maintain their benefits in the field and whether they will increase the parasitism rate of H. halys.


2019 ◽  
Vol 151 (2) ◽  
pp. 209-218 ◽  
Author(s):  
A.E. Gradish ◽  
H. Fraser ◽  
C.D. Scott-Dupree

AbstractHalyomorpha halys(Stål) (Hemiptera: Pentatomidae) is a serious invasive pest of many agricultural and horticultural crops in Canada and the United States of America. To mitigate economic loss for growers, effective management options forH. halysare needed. We evaluated the efficacy of 12 insecticides (Beauveria bassiana(Balsamo-Crivelli) Vuillemin (Cordycipitaceae), boric acid, chlorpyrifos, clothianidin, flupryadifurone, λ-cyhalothrin, malathion, novaluron, sulfoxaflor, thiamethoxam, thiamethoxam + λ-cyhalothrin, and thiamethoxam + novaluron) currently used or with potential forH. halysmanagement by determining their direct and residual contact toxicity toH. halysnymphs. Each insecticide was tested at its Canadian label rate and half and twice that rate. With the exception of chlorpyrifos, nymph mortality was low (< 40%) following direct or residual contact exposure to all insecticides and rates. All surviving nymphs were severely affected (i.e., knocked down) by direct and residual contact exposure to neonicotinoids, while approximately 66% of nymphs were severely affected following exposure to sulfloxaflor residues at label and twice label rate. However, few nymphs were severely affected by all other insecticides and rates. Overall, our results suggest thatH. halysis not susceptible to many insecticides at current label rates for Canada. More research is needed to identify efficacious insecticides forH. halys.


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